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//! Provides `Mutex` and `MutexGuard`
pub use implementation::{Mutex, MutexGuard};
#[cfg(feature = "std")]
use std::sync as implementation;
#[cfg(not(feature = "std"))]
mod implementation {
use crate::sync::{LockResult, TryLockError, TryLockResult};
use core::fmt;
pub use spin::MutexGuard;
/// Fallback implementation of `Mutex` from the standard library.
pub struct Mutex<T: ?Sized> {
inner: spin::Mutex<T>,
}
impl<T> Mutex<T> {
/// Creates a new mutex in an unlocked state ready for use.
///
/// See the standard library for further details.
pub const fn new(t: T) -> Self {
Self {
inner: spin::Mutex::new(t),
}
}
}
impl<T: ?Sized> Mutex<T> {
/// Acquires a mutex, blocking the current thread until it is able to do so.
///
/// See the standard library for further details.
pub fn lock(&self) -> LockResult<MutexGuard<'_, T>> {
Ok(self.inner.lock())
}
/// Attempts to acquire this lock.
///
/// See the standard library for further details.
pub fn try_lock(&self) -> TryLockResult<MutexGuard<'_, T>> {
self.inner.try_lock().ok_or(TryLockError::WouldBlock)
}
/// Determines whether the mutex is poisoned.
///
/// See the standard library for further details.
pub fn is_poisoned(&self) -> bool {
false
}
/// Clear the poisoned state from a mutex.
///
/// See the standard library for further details.
pub fn clear_poison(&self) {
// no-op
}
/// Consumes this mutex, returning the underlying data.
///
/// See the standard library for further details.
pub fn into_inner(self) -> LockResult<T>
where
T: Sized,
{
Ok(self.inner.into_inner())
}
/// Returns a mutable reference to the underlying data.
///
/// See the standard library for further details.
pub fn get_mut(&mut self) -> LockResult<&mut T> {
Ok(self.inner.get_mut())
}
}
impl<T> From<T> for Mutex<T> {
fn from(t: T) -> Self {
Mutex::new(t)
}
}
impl<T: Default> Default for Mutex<T> {
fn default() -> Mutex<T> {
Mutex::new(Default::default())
}
}
impl<T: ?Sized + fmt::Debug> fmt::Debug for Mutex<T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let mut d = f.debug_struct("Mutex");
match self.try_lock() {
Ok(guard) => {
d.field("data", &&*guard);
}
Err(TryLockError::Poisoned(err)) => {
d.field("data", &&**err.get_ref());
}
Err(TryLockError::WouldBlock) => {
d.field("data", &format_args!("<locked>"));
}
}
d.field("poisoned", &false);
d.finish_non_exhaustive()
}
}
}